The present invention relates to an inspection method and an inspection apparatus for a thermal assist type magnetic head element that inspect a thermal assist type light emitting portion and a magnetic field generating portion of a thermal assist type magnetic head element by measuring a minute heat source with a scanning probe microscope.
Thermal assist type magnetic head elements, such as magnetic heads disclosed in JP 2010-182394 A (Patent Document 1), JP 2011-86362 A (Patent Document 2), and JP 2011-113595 A (Patent Document 3), have been examined as a magnetic head for a next-generation hard disk. Thermal assist light generated from a thermal assist type magnetic head element, that is, near-field light is in a width range of several tens or less nanometers (nm), and the spatial distribution of light spots, and the energy density or the absolute temperature as a heat source determine the writing track width of a hard disk. When the thermal assist type magnetic head element operates actually, an inspection method for information about the spatial intensity distribution of near-field light spots and the like is an important unsolved problem.
Meanwhile, techniques for measuring minute light-emitting areas, such as near-field light spots of a thermal assist type magnetic head element, on the basis of a scanning probe microscope (SPM) inspection technique are disclosed in JP 2009-230845 A (Patent Document 4) and Phys. Rev. Lett. 85, 3029 (Non-Patent Document 1).